Conventionally in forming bumps on electrodes of ICs (integrated circuits), bumps have been formed on every one of IC chips, i.e., an individual piece cut one by one from a semiconductor wafer. A conventional bump formation method is inferior in productivity because it requires a transfer time for each individual piece to be transferred to a bump bonding apparatus to form bumps. For shortening the transfer time, an arrangement of transferring a semiconductor wafer to the bump bonding apparatus to form bumps on the ICs on the semiconductor wafer has come to be performed.
When bumps are to be formed on ICs on the semiconductor wafer, it is necessary to recognize positions of the ICs to form bumps on electrodes of the ICs. The semiconductor wafer itself is heated to approximately 150-200° C. when bumps are formed, and this heating affects the bump bonding apparatus as well, e.g., thermally expands the apparatus or the like. As such, a mark for position recognition formed on each IC has been conventionally imaged by a recognition camera for every IC before the bumps are formed on each IC, thereby correcting a position of the semiconductor wafer.
The semiconductor wafer has, for example, nearly 3000-10000 ICs formed thereon. The larger the number of ICs, the more time it takes for positional recognition to form bumps. When for instance, 2-4 bumps are formed on each IC, forming one bump takes approximately 60-80 msec. On the other hand, recognizing one position recognition mark requires approximately 200-250 msec. Since two position recognition marks should be recognized for every IC, the time required for positional recognition is considerably long as compared with the time for forming bumps, thereby deteriorating productivity.